“A son of grace is Yosef, a son of grace to the eye; girls stepped up to gaze” (Bereishit 49:22)
Rashi interprets the words to gaze as referring to the fact that the evil eye would not affect his offspring. Also, when Yaakov blessed Efrayim and Menashe, he blessed them that they should be like fish, over which the evil eye has no effect.
The Midrash relates (Midrash Rabbah, Bamidbar 12:4) that Rabbi Yehoshua of Sachnin says in the name of Rabbi Levi: This can be compared to a king who prepared a lavish wedding for his daughter. The evil eye took control of her. What did the king do? He gave her an amulet for protection, telling her to wear it always in order to ward off the evil eye.
So did Hashem do at the time of Matan Torah. He made a great celebration, as the pasuk says, “The entire nation saw the thunder.” They were all holy, as Hashem told Moshe, “Go to the nation and sanctify them today and tomorrow.” But an evil eye took control over them, and the luchot were broken…
When the time came to build the Mishkan, Hashem gave them the blessings first, so that no evil eye take hold of them. This is why it says, “May Hashem bless you and protect you from the evil eye,” and then, “It was on the day that Moshe finished…”
Tzipporah, wife of Moshe, was called a kushit (black-skinned), due to her excessive beauty. This is like one who calls his handsome son by a derogatory name, in order to ward off the evil eye (Tanchuma, Tzav 96:13).
In Megillat Rut (1:5), we read, “The two of them, Machlon and Kilion, also died.” This teaches that the evil eye strikes at one’s children (Yalkut Shimoni, Rut 1:420).
Which is the evil path from which a man should distance himself? Rabbi Eliezer says: An evil eye (Avot 2:9).
Rabbi Yosi says in the name of Rabbi Chanina: The sons of Yosef are compared to the fish of the sea. Just as fish are covered by water, and are thereby protected from the evil eye, so are the offspring of Yosef protected from the evil eye. This is most appropriate, for Yosef refused to indulge in something that did not belong to him. Therefore, the evil eye has no control over him (Berachot 20a).
Rabbi Abahu says in the name of Rav Huna, who quotes Rav: It is forbidden for a person to stand in his friend’s field when it is in full harvest (Bava Metzia 107a).
“And Hashem shall remove from you all sickness.” Rav says this refers to the evil eye… He went up to the cemetery, performed certain segulot, and then said, “Ninety-nine have died through an evil eye and one through natural causes” (Bava Metzia 107b).
Rabbi Dessler (Michtav Me’Eliyahu IV, pg. 5) asks: How can one be spared from the evil eye? He replies with the following. When a person is jealous of his friend and gazes at him with an evil eye, this has the potential to harm his friend. How is his friend guilty, that he deserves the Attribute of Justice to punish him? It could be that he unwittingly aroused his friend’s jealousy. It is tried and true that one who lives for the sake of others and is a giver and not a taker, will never awaken jealousy in others. Our Sages attest about the offspring of Yosef, “The evil eye never controlled them, as the pasuk states, ‘A son of grace is Yosef, a son of grace to the eye.’ The eye which did not want to indulge in what was not his, will never be controlled by the evil eye.”
